Who nearly cracked bitcoin

1.

bitcoin is just a game. If it is promoted as a tool to get rich, it can be regarded as a fraud. Just like the currency in other online games, the only difference is that bitcoin has been standardized since the game was first formulated. It can't be issued indiscriminately, so it can keep its value better than other virtual game props. It is equivalent to the online collection. Bitcoin is a prop in the game, and its value is reflected in the recognition of bitcoin by players: more people play, the value of props in the game is higher; The risk is that he is not the only game, and his algorithm is not the only one. Maybe someone will be able to make other special coins soon. All you need to do is promote the game and sell your props. As for money, bitcoin does not have the basic attributes of money, such as unfair initial distribution and insecure circulation. Money needs to be maintained by the state machine

< H2 > extended materials:

the concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's ideas, the open source software and the P2P network on it were designed and released. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system. Unlike most currencies, bitcoin does not rely on specific currency institutions to issue. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses cryptography design to ensure the security of all aspects of money circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction

1. Bitcoin (bitcoin) is a kind of network virtual currency, which can buy real-life goods. It is characterized by decentralization, anonymity, and can only be used in the digital world. It does not belong to any country or financial institution, and is not subject to geographical restrictions. It can be exchanged anywhere in the world. Therefore, it is used as a money laundering tool by some criminals

2. On January 7, 2014, Taobao announced that it would ban the sale of Internet virtual currencies such as bitcoin and lightcoin from January 14. On February 26, 2014, Democratic Senator Joe Manchin of West Virginia issued an open letter to a number of regulatory authorities of the federal government of the United States, hoping that relevant institutions would pay attention to the status quo of bitcoin encouraging illegal activities and disrupting the financial order, and demanded that actions be taken as soon as possible to completely ban the electronic currency

3. On May 12, 2017, a global outbreak of bitcoin virus madly attacked public and commercial systems! Nearly 74 countries in the world have been seriously attacked

4. From August 1, 2017, global bitcoin trading platform will suspend recharge and withdrawal services. Bitcoin China digital asset trading platform will stop new user registration on September 14, and all trading businesses will be stopped on September 30

< H2 > reference materials:

network bitcoin

2. First of all, let's talk about the background. The basic principle of bitcoin "account" is key public key address. You can roughly understand it as "key box box number". Now is to start from the box number or box to crack the key
there are basically two kinds of attacks, one is dictionary attack, the other is brute force attack
dictionary attack is to use common passwords and their simple variants as keys one by one. As long as your pass phrase is not hard enough, the possibility of successful attack is very high. So if you want to use this, you need to popularize the knowledge of cryptography first, and don't think it's very safe to add a long password
if you don't use the wallet generated by pass phrase, you can only crack it violently, which is equivalent to enumerating all the possible keys. At present, this is impossible, even if the electronic computer is becoming more and more powerful. However, quantum computer can do it theoretically, but don't worry too much. If such a powerful quantum computer comes out, it will not only endanger bitcoin
at the same time, bitcoin has a second layer of protection: if an address only accepts bitcoin but does not output it, its public key is confidential, that is to say, no one else can see the box, only the box number. At present, the process of decing the box from the box number can't even be done by quantum computer. In other words, if there is a quantum computer, bitcoin has a last line of Defense: it's temporarily safe to transfer your money to a new address
finally, some time ago, the wallet generated by the Android client was attacked because of a bug in the underlying random number generator. In fact, this function is not random securerandom, which Google quickly admitted and fixed. It's hard to say whether this kind of thing will happen again, but I don't think we need to worry too much.

3. The concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's idea, open source software was designed and released, and P2P network was built on it. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system

unlike most currencies, bitcoin does not rely on specific currency institutions. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses the distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses the design of cryptography to ensure the security of all aspects of currency circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction. The design based on cryptography can make bitcoin only be transferred or paid by the real owner. This also ensures the anonymity of money ownership and circulation transactions. The biggest difference between bitcoin and other virtual currencies is that the total amount of bitcoin is very limited and it has a strong scarcity. The monetary system used to have no more than 10.5 million in four years, after which the total number will be permanently limited to 21 million

bitcoin can be cashed and converted into the currency of most countries. Users can use bitcoin to buy some virtual items, such as clothes, hats and equipment in online games. As long as someone accepts it, they can also use bitcoin to buy real-life items< On February 26, 2014, Joe Manchin, a Democratic senator from West Virginia, issued an open letter to a number of regulatory authorities of the US federal government, hoping that relevant institutions would pay attention to the status quo of bitcoin's encouraging illegal activities and disrupting the financial order, and demanded that actions be taken as soon as possible to completely ban the electronic currency.

4. No, there are several reasons why bitcoin was stolen
1. A stolen bitcoin can't be retrieved, and if it's lost, it's lost.
2. Bitcoin has transaction records, but the address is hidden, and you can't find an indivial.
3. Every bitcoin has a key, and only if you have this key can you be admitted to own bitcoin. However, if bitcoin is stolen or lost, your bitcoin will disappear completely
therefore, the theft of bitcoin does not belong to cracking, it may be e to internal personnel.

5. Caibi tix is good. It can be said that caibi tix is the first potential virtual currency in 2018. Many people buy it, and its appreciation is fast.

6. Theoretically, it can be cracked, but it's just a time-consuming problem. If you think about the cost of mining, you should know the difficulty of cracking. To protect bitcoin by means of encryption must make the cracker pay a much higher price than mining, otherwise everyone can get it by cracking rather than mining

7. Because the cost of encryption is much less than decryption,
suppose that a supercomputer can violently try 1 billion passwords in one second by setting a password with numbers and uppercase and lowercase letters (a total of 62 characters), then:
it takes 1 second to crack 5-digit passwords (62 ^ 5 = 920 million),
it takes 62 seconds to crack 6-digit passwords,
it takes 1 hour to crack 7-digit passwords,
it takes 2.5 days to crack 8-digit passwords,
it takes half a year to crack 9-digit passwords,
it takes 100000 years to decipher 12 (more than the history of human civilization),
it takes 24.3 billion years to decipher 15 (more than the age of the universe)
the 15 bit password takes a few seconds to input more than the 5-bit password, but the decryption cost is almost impossible
even if the quantum computer can increase the cracking speed by 100 million times, it will only offset 27 bits of the 256 bit private key length of bitcoin (2 ^ 27 = 130 million). Even if extraterrestrials appear and the cracking speed is increased by 100 million times for several times in a row (each time the length of the private key is offset by 27 bits), bitcoin can simply upgrade the length of the private key to 512 bits.

8. Mining software refers to bitcoin mining,
the general process is to use the computer's CPU and / or image processor to calculate bitcoin information
for Internet cafes and users, it will greatly rece computer resources:

program operation is very slow
crash
blue screen

and so on

9. Wannacry uses the vulnerability of 445 port of Windows operating system to spread, and has the characteristics of self replication and active propagation
after being invaded by the blackmail software, almost all kinds of files such as photos, pictures, documents, audio and video in the user's host system will be encrypted, and the suffix of the encrypted files will be changed to. Wncry, and a blackmail dialog box will pop up on the desktop, asking the victim to pay hundreds of dollars worth of bitcoin to the attacker's bitcoin wallet, And the amount of ransom will increase over time.

10.

Of course, that's enough. Even if you use something more advanced in the future, you can learn it now

because you'll never be able to prepare 100% of the PY knowledge you need for TF, you've got 7788

now, when